Environment

Coral Reef in Caribbean Facing Previously Unknown Threat - Algal Crusts

While many people are now familiar to the threat posed to the planet's coral reefs due to warming seas that cause bleaching and eventual death of the coral polyps, scientists say there is a new, urgent threat being faced by the tiny creatures which contribute so heavily to the stability and security of life on shore.  A paper published this month in Cell, a scholarly magazine devoted to biology, identifies peyssonnelid algal crusts, or PACs, as a deadly threat that scientists have been missing for years. Authors Peter Edmunds, Thom Schils and Bryan Wilson described the seabed in the shallow waters off the coast of St. John USVI as being up to 64 percent covered in PACs as of 2019.  These PACs have eluded scrutiny for so long, the scientists say, because they are so nondescript and difficult to identify. "PAC may be confused for similar looking seaweeds," the paper notes. Biological classification has therefore proven difficult, with many PACs assigned to incorrect groupings, leading ...